This 2017-2018 Ground Collision Severity Evaluation focused on increased testing to validate the hypothesis and findings of our earlier ASSURE Ground Collision Severity Evaluation and its associated Part 107 Waiver Case Study. This ASSURE team included The University of Alabama in Huntsville, The National Institute for Aviation Research at Wichita State University, The Ohio State University, and Mississippi State University. The goal for this team was to assess injury potential of various SUAS of different material properties and construction. The team conducted fixed wing and multirotor SUAS failure flight testing and aerodynamic modeling, full anthropomorphic test device (ATD) impact testing, simplified head and neck only ATD impact testing, ATD and human‐body model impact simulations, Post Mortem Human Surrogate (PMHS) impact testing, and high-fidelity head and neck only impact simulations. During this project, researchers collected data on over 41 flight test points, 155 simplified impact tests, 133 ATD impact tests, 41 PMHS impact tests, over 100 full-ATD and human-body model impact simulations, and 15 high-fidelity head and neck simulations. Tests were conducted with 16 different multi-rotor and fixed-wing SUAS and objects (payloads, wood blocks and batteries) with weights ranging from 0.75 - 13.2 lbs.
The ATD and PMHS testing provided insight into the applicability of automotive injury criteria in SUAS impact scenarios. In addition, experimental testing provided calibration data for ATD and human-body models, and correlation of ATD responses to PMHS injury data. The PMHS testing also enabled assessment of assumed injury thresholds from our previous studies. Only one out of 33 high-speed drone impacts during PMHS testing resulted in one observable skeletal injury. The PMHS testing and analysis of the injury data strongly support our previous study's assessment that the Range Commanders Council (RCC) probability of fatality data is overly conservative and largely not applicable to elastic SUAS. The preliminary injury thresholds for SUAS head impacts developed in our earlier work were also overly conservative. Additional PMHS testing is needed to develop more accurate probability-based injury risk curves, similar to those used by the automotive industry, but relevant to the impact characteristics of SUAS. Until they are, we recommend that the FAA use the automotive based injury criteria called out in this report as well as previously developed risk thresholds that have been further developed in this study to assess when additional operational risk mitigations are required to reduce the probability of serious injury.